I. Field of the Invention
The present invention relates generally to fuel systems for internal combustion engines and, more particularly, to a fuel system component for a direct injection internal combustion engine.
II. Description of Related Art
Direct injection internal combustion engines have enjoyed increased popularity due to the enhanced efficiency and increased fuel economy of such engines. In a direct injection engine, a fuel injector is positioned in the engine block so that one end of the injector is open to the combustion chamber.
With reference to FIGS. 1 and 2, a prior art fuel injector 10 is shown. The fuel injector 10 includes an elongated body 12 which is mounted within a bore in the engine block so that an end 14 of the fuel injector body 12 is open to the engine combustion chamber. One or more seals 16, furthermore, seal the injector body to the engine block.
The body 12 of the fuel injector 10 is mounted to a fuel rail 18. The fuel rail 18 is pressurized with fuel by a fuel pump and supplies that fuel to the fuel injectors 10 attached to the fuel rail 18. The fuel rail 18, in turn, is typically attached to the engine block by a bracket 20.
Both the timing and duration of the fuel pulses out the end 14 of the fuel injector 10 and into the combustion chamber is controlled by valving contained within the fuel injector 10. In order to actuate that valving, an injector connector 22 is attached to each fuel injector 10. The injector connector 22 includes an elongated injector connector portion 24 as well as a terminal 26 and is connected to the harness assembly. The terminal 26 is electrically connected to the fuel management system for the engine which controls the timing and duration of the fuel injection pulses by electrical signals provided through the terminal 26.
As best shown in FIG. 2, conventionally the injector connector 24 as well as the terminal 26 extends laterally outwardly from the fuel rail 18 when viewed along the axis of the fuel injector body 12. Thus, with the fuel rail 18 overlying the fuel injector body 12, both the injector connector 24 as well as the terminal 26 protrudes laterally outwardly from one side of the fuel rail 18.
The fuel pressures required by a direct injection engine greatly exceed the fuel pressures utilized by the previously known multipoint injectors. Consequently, in order to prevent movement of the fuel injectors 10 in operation, the fuel injector 10 is conventionally rigidly attached to the fuel rail 18 which, in turn, is rigidly attached to the engine block by the injector connector 20.
These previously known direct injection engines, however, suffer from several disadvantages. First, since the fuel injectors 10 are rigidly mounted to tie fuel rail 18, the fuel rail 18, together with its attached fuel injectors 10, must be removed from the engine block as a unit when service is required. However, in some engines, an attempt to remove the fuel rail 18 with its attached fuel injectors 10 creates an interference between the harness assembly 22 and other components in the engine. Consequently, when removal of the fuel rail 18 with its attached fuel injectors 10 is required, partial disassembly of the engine is also required. This, however, disadvantageously increases the overall servicing cost for the engine.
A further disadvantage of the previously known fuel rail and fuel injector components is that the attachment of the bracket 20 to the engine block is offset from the axis of the fuel injector body 12. This, in turn, creates a torque on the fuel injector from the discharge of fuel through the end 14 of the fuel injector body 12. This torque, over time, can create stresses in the components of the fuel injector system. In extreme cases, these stresses may result in fracture, cracking or other failure of the fuel system components for the direct injection engine.
Summary of the Present Invention